Nonwoven composite abrasives commonly are employed to polish or finish a wide range of metallic surfaces. While suitable for polishing most metals, conventional nonwoven abrasives have a tendency to leave a visible residue on the metal surface of high-temperature alloys, such as titanium-based alloys. This residue is typically known as “smear” and its presence is considered deleterious. The amount of smear present typically is directly proportional to the density of the nonwoven composite abrasive employed to polish the metal.
Smear has been identified as being composed primarily of polyurethane resin, often with trace amounts of nylon. Polyurethane resin is a common bonding adhesive used in nonwoven abrasives, while nylon is a fiber that is employed as a substrate for composite abrasives.
In order to reduce smearing, external lubricants, such as talc, kaolin, metallic stearates (such as zinc stearate, calcium stearate or lithium stearate) and tetrafluoroethylene (such as in powder form) often are added to the polyurethane adhesive. The amount of these external lubricants, however, typically has a limited effect on reducing the presence of smear, and significantly reduces the product life of the nonwoven composite abrasive as a consequence of concomitant increased product shed.
Therefore, a need exists to significantly reduce or eliminate the above-referenced problems associated with nonwoven composite abrasives.